A new study says some common soaps, shampoos and other personal care products may be putting adolescent girls at a higher risk of certain cancers and other developmental issues.

Researchers at the University of California, Berkeley, have found that chemicals known as phthalates, parabens and phenols have all been linked to girls entering puberty at earlier ages. Their findings were published recently in the journal Human Reproduction.

Parabens are used for preserving, and phenols are included for durability in personal hygiene products. Phthalates are used in beauty products such as cosmetics, nail polishes and perfumes to improve look and feel of the substance. These chemicals are believed to be endocrine disruptors for their ability to interfere with the body’s natural hormone regulation. In adolescents, experts say, this may mean advanced reproductive maturing — defined by signs of puberty, namely menstruation, in girls as young as 8 to 11.

The effects these chemicals have on female reproductive hormones aren’t limited to the direct user, but in fact, harm infant girls whose mothers used these products while pregnant.

“This is important, because we know that the age at which puberty starts in girls has been getting earlier in the last few decades; one hypothesis is that chemicals in the environment might be playing a role, and our findings support this idea,” Dr. Kim Harley, associate professor at U.C. Berkeley and the study’s lead author, says in a statement.

“Earlier puberty in girls increases their risk of mental-health problems and risk-taking behavior as teenagers and increases their risk of breast and ovarian cancer over the long-term, so this is an important issue to address.”

Researchers followed 179 girls and 159 boys from birth to adolescence between 1999 and 2000, and took urine samples at key ages to gauge the level of phthalates, parabens and phenols. They also collected samples from their pregnant mothers before they were born.

Over 90 percent of samples contained these endocrine disruptors. Those who showed double the concentration of phthalates had girls who developed pubic hair 1.3 months earlier than typical girls. Certain phenols contributed to a one-month shift earlier in girls’ first menstruation.

Parabens appeared to have the most intrusive impact, causing girls to develop breasts, pubic hair and their first menstruation about one month sooner. There was no similar association for boys.

Phthalates, parabens and phenols are not easy to avoid. The Centers for Disease Control and Prevention’s National Health and Nutrition Examination Survey found that 96 percent of women in the study tested positive for these chemicals.